Use isa<> instead of checking return value of definition().

[ruiu]

Summary

definition() is supposed to be used through isa, dyn_cast or cast.
It's better to not call that directly.

[kledzik]

LGTM

lib/ReaderWriter/MachO/GOTPass.cpp

void perform(std::unique_ptr<MutableFile> &mergedFile) override {
 
     // add all created GOT Atoms to master file
     for (auto &it : _targetToGOT)
       mergedFile->addAtom(*it.second);
   }
 
   bool shouldReplaceTargetWithGOTAtom(const Atom *target, bool canBypassGOT) {
     // Accesses to shared library symbols must go through GOT.
-    if (target->definition() == Atom::definitionSharedLibrary)
+    if (isa<SharedLibraryAtom>(target))
       return true;
     // Accesses to interposable symbols in same linkage unit must also go
     // through GOT.
     const DefinedAtom *defTarget = dyn_cast<DefinedAtom>(target);
     if (defTarget != nullptr &&
         defTarget->interposable() != DefinedAtom::interposeNo) {
       assert(defTarget->scope() != DefinedAtom::scopeTranslationUnit);
       return true;

lib/ReaderWriter/MachO/StubsPass.cpp

void perform(std::unique_ptr<MutableFile> &mergedFile) override {
     // Scan all references in all atoms.
     for (const DefinedAtom *atom : mergedFile->defined()) {
       for (const Reference *ref : *atom) {
         // Look at call-sites.
         if (!this->isCallSite(*ref))
           continue;
         const Atom *target = ref->target();
         assert(target != nullptr);
-        if (target->definition() == Atom::definitionSharedLibrary) {
+        if (isa<SharedLibraryAtom>(target)) {
           // Calls to shared libraries go through stubs.
           replaceCalleeWithStub(target, ref);
           continue;
         }
         const DefinedAtom *defTarget = dyn_cast<DefinedAtom>(target);
         if (defTarget && defTarget->interposable() != DefinedAtom::interposeNo){
           // Calls to interposable functions in same linkage unit must also go
           // through a stub.